Field of the Invention
The present invention pertains to covered vessels, such as so-called "commuter mugs. " Such vessels usually include a cup, often with a handle, and a cover or lid to prevent liquid within the cup from spilling, e.g. if the cup is carried in a moving vehicle. However, such vessels can, of course, also be used in any environment, and in any case, their covers can also perform other functions. For example, such a cover may help to insulate either a hot or cold beverage, or if the cup is being used outdoors, the cover may help to prevent wind-borne dust, leaves, or the like from being blown into the cup.
In such a cup, the lid is usually equipped with some type of valve which allows the user to drink from the cup without removing the entire lid.
Such cups as are currently available have room for improvement, particularly in the area of ergonomics, but also in other areas. For example, many such cups have a valve arrangement which opens only a very small hole in the lid, and the effect of drinking from such a hole may be uncomfortable. The hole is often formed in a generally flat lid member which is recessed sharply down from an upstanding rim perpendicular thereto. This can increase the discomfort of drinking from the hole and/or can allow liquid emerging from the hole to flow all over the flat surface before being drunk, thereby messing the outside of the lid and potentially picking up the very contamination which the lid would otherwise exclude from the liquid. Prior attempts to remedy this situation have only been partly successful, and have resulted in asymmetrical, and relatively unattractive designs.
Another problem with such prior art cups is that they are often only convenient for drinking by a right-handed person, or perhaps by a left-handed person, but a given cup is not comfortable for right-handed people as well as left-handed people.
Still other problems revolve around the mechanism for operating the valve. In some prior art devices, the valves, or in some cases, the entire lids, open outwardly. Although this can be accomplished with a fairly simple actuating mechanism, it can interfere with the user's face. On the other hand, prior art valves opening inwardly have typically been actuated by undesirably complicated mechanisms.
Still other problems with the prior art actuating mechanisms again have to do with ergonomics, as when the action which must be performed by the user in order to open the valve does not so easily arise from a natural position of he fingers and the hand while holding the cup for drinking.